The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Recently, increasing oil prices have caused vehicle manufacturers all over the world to rush into infinite competition. Particularly in the case of engines, manufacturers have been pursuing efforts to reduce the weight and improve fuel efficiency of vehicles by reducing engine size, etc.
As for an automatic transmission, there are various methods of improving fuel efficiency, and operability and competitiveness in fuel efficiency can both be secured by implementing multiple steps of shifting.
However, when the shift ranges increase, the number of parts in an automatic transmission also increases, so the automatic transmission may be difficult to mount, the manufacturing cost and weight may be increased, and power transmission efficiency may be deteriorated.
Accordingly, in order to increase the effect of improving fuel efficiency through multiple steps of shifting, we have discovered that it may be important to develop a gear train structure that can achieve maximum efficiency with fewer parts.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.